Isoascorbate

Isoascorbate (Isoascorbic Acid / Erythorbic Acid): A Comprehensive Reference

1. Identity and Nomenclature

Isoascorbate — most precisely the anionic form of isoascorbic acid — is encountered in scientific, regulatory, and commercial literature under an extensive array of synonyms. Chemical names listed by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) include sodium isoascorbate, sodium D-isoascorbate, and 3-keto-D-gulofuranolactose sodium enolate monohydrate. JECFA lists sodium isoascorbate as a synonym for sodium erythorbate, and both correspond to INS 316 / E316. Additional names encountered in the peer-reviewed literature include D-araboascorbic acid, erythorbic acid (for the free acid form), D-isoascorbic acid, and mercate 5. The compound carries CAS numbers 7378-23-6 (sodium salt) and 89-65-6 (free acid).

Erythorbic acid is a stereoisomer of ascorbic acid that differs from ascorbic acid only in the relative position of the hydrogen and hydroxyl groups on the fifth carbon atom in the molecule. More precisely, its epimer erythorbic acid (also known as isoascorbic acid or D-araboascorbic acid) is used as a food additive; however, it is only poorly retained by tissues and is more rapidly excreted from the human body. The molecular formula is C₆H₇NaO₆ for the sodium salt and C₆H₈O₆ for the free acid.

Common Forms and Preparations

• Free acid (erythorbic acid / isoascorbic acid, E315): occurs as white or slightly yellow-colored crystals or powder, which gradually darken in color upon exposure to light. In the dry crystalline state it is nonreactive, but in water solutions it reacts readily with atmospheric oxygen and other oxidizing agents, making it valuable as an antioxidant.
• Sodium salt (sodium erythorbate / sodium isoascorbate, E316): PubChem describes it as forming white, free-flowing crystals and identifies it as a synthetic antioxidant used in food and cosmetic formulations. It has a solubility of 15 g in 100 mL of water at 25 °C.
• Lipophilic ester derivative (D-isoascorbyl palmitate): A fatty acid ester synthesized for use in oil-soluble applications; its development has been investigated to overcome isoascorbic acid's highly hydrophilic character, which limits its use in fat-based or cosmetic formulations.

2. Natural Sources and Biosynthesis

Erythorbic acid is a polar antioxidant compound that is sensitive to light and stable in dry state. It is naturally produced by yeast and also synthesized by acidification of calcium 2-keto-D-gluconate. It can also be produced from Penicillium spp. Specifically, erythorbic acid is very easily produced by fermentation, being obtainable in just one step compared to ascorbic acid's two. A number of Penicillium species naturally produce this chemical from glucose; this is the original process developed in the 1960s, but it has low volumetric efficiency and glucose yield compared to the modern method.

Unlike L-ascorbic acid (vitamin C), isoascorbic acid is not found in meaningful quantities in common fruits or vegetables consumed by humans. Its occurrence as a natural metabolite is largely limited to lower organisms such as yeasts and fungi. Isoascorbic or erythorbic acid is a stereoisomer of ascorbic acid acting as a preservative against oxidation and decoloration.

Industrial Production

Today the industrial process is quite similar to the Reichstein process used for ascorbic acid, only chirally flipped. Microbial fermentation first produces a 2-keto-sugar acid — for example, by Pseudomonas fluorescens AR4 converting glucose to 2-keto-D-gluconate — followed by chemical rearrangement to produce the product. Erythorbate is produced by means of a complex and long process after bio-fermentation of dextrose. The sodium salt form is then obtained by neutralization of the free acid with sodium hydroxide or sodium carbonate.

3. Traditional and Historical Use

Isoascorbic acid, in contrast to L-ascorbic acid (vitamin C), has no documented history of traditional use in any specific cultural or ethnobotanical tradition as a medicine or health supplement. It is entirely a product of twentieth-century food science and industrial chemistry. Isoascorbic or erythorbic acid is a stereoisomer of ascorbic acid acting as a preservative against oxidation and decoloration, recently approved for food use also in the European Market — with the first JECFA evaluations appearing as early as 1961. JECFA records show evaluations dating back to 1961 (NMRS 31/TRS 228-JECFA 6) and subsequent reviews in 1971, 1973, and 1990.

Since the FDA banned the use of sulfites as a preservative on raw fruits and vegetables in 1986, the use of erythorbic acid has increased. Its role in meat curing, however, predates this expansion: the cured meats in the human diet have a history of thousands of years, but the deliberate addition of isoascorbate/erythorbate to meat curing processes was a mid-twentieth-century development, employed specifically to accelerate the nitrite-to-nitric oxide conversion and reduce residual nitrite content, thereby improving both safety and color stability in processed meat products.

4. Key Constituents and Active Compounds

Isoascorbate itself is the active chemical species; it is not a plant extract or multi-component preparation. Its biological and technological activities derive directly from its molecular structure.

Structural Relationship to Ascorbic Acid

Chemically, sodium erythorbate is a stereoisomer of ascorbic acid (vitamin C), but it has no nutritional value as vitamin C. The two molecules share the same molecular formula (C₆H₈O₆) and the same general lactone ring scaffold but are epimers at C-5, meaning the spatial arrangement of substituents at that carbon atom is inverted. Erythorbic acid (EA), one of the AA epimers, has reduced vitamin C activity, while the antioxidant activity of EA is similar to that of AA.

Mechanisms of Action

Oxygen scavenging (primary antioxidant mechanism): Its antioxidant mechanism (same with sodium erythorbate and ascorbic acid) is as an oxygen scavenger that reacts with oxygen to reduce the oxygen content in food. This distinguishes it from lipid-soluble, chain-breaking antioxidants (e.g., BHA, BHT, TBHQ), which work by donating hydrogen free radicals to interrupt radical autoxidation chains.

Reducing agent (electron donor): Sodium erythorbate is the sodium salt of erythorbic acid, a stereoisomer of ascorbic acid. Chemically, it behaves as a strong reducing agent, meaning it readily donates electrons — which is exactly why food manufacturers use it: it can slow oxidation processes that cause off-flavours, colour changes, and quality loss during storage.

Nitrite reduction in meat curing: In meat curing, sodium erythorbate functions as an antioxidant to increase the rate of nitrite reduction to nitric oxide, which reduces the amount of residual nitrite in cured meat after curing sufficiently took place. To prevent nitrosamine formation, antioxidants such as ascorbate and erythorbate are added to meat formulations; these compounds inhibit nitrosamine formation by reducing HNO₂ to nitric oxide (NO), a far less reactive and non-nitrosating species. This protective mechanism is especially relevant during cooking, when heat and moisture promote nitrite degradation and potential nitrosation reactions.

Metal chelation: Erythorbic acid is a metal-chelating agent where it partly deactivates trace metals that are often present as salts of fatty acid, which would otherwise cause oxidative damage.

Free radical scavenging and reducing power: The admirable antioxidant potential of erythorbic acid is imparted by its metal chelation property, free radical scavenging and reducing power.

Transporter Selectivity Compared to Ascorbic Acid

Two Na⁺-dependent L-ascorbic acid transporters, the sodium-dependent vitamin C transporters 1 and 2 (SVCT1 and SVCT2), have been cloned and shown to be expressed in intestinal absorptive cells. The level of expression of SVCT1 is markedly higher than that of SVCT2, and SVCT1 appears to play a more important role in the overall intestinal AA absorption process. Both transporters have higher selectivity for L-ascorbic acid than for D-isoascorbic acid and dehydroascorbic acid; also, they both transport L-ascorbic acid via an electrogenic Na⁺-dependent process (stoichiometric ratio of 2:1 for Na⁺ to ascorbic acid). This transporter selectivity is a principal reason why D-isoascorbic acid is poorly retained in human tissues compared to L-ascorbic acid.

5. Scientific Evidence by Area of Use

5.1 Antioxidant Activity in Food Systems

The antioxidant function of isoascorbate in food processing is the most rigorously established application, supported by extensive regulatory review rather than clinical trials in humans. According to the European food safety assessment, erythorbic acid and sodium erythorbate in combination are authorized as food preservatives with highest permissible levels of 250–1500 mg/kg or mg/L in different food categories.

Erythorbate is more thermally stable than ascorbic acid and retains its antioxidant properties longer under heat exposure, making it more effective in cooked or fried meat products. This thermal stability advantage over L-ascorbate is of practical significance during high-temperature processing steps such as frying or smoking.

Evidence strength: Well-established for technological food applications; supported by decades of regulatory review by JECFA, EFSA, and FDA.

5.2 Nitrosamine Inhibition in Cured Meats

Sodium erythorbate is an antioxidant that converts nitrite to nitric oxide, thereby speeding up this conversion and increasing the color of meat products. Meanwhile, it can reduce the amount of nitrites used in meat products and the amount of residues, and therefore effectively reduce the formation of nitrosamines, which are carcinogens.

In the modern curing plant, speeding up the formation of nitric oxide from nitrite is important because it speeds up the curing time, but far more important, it reduces the nitrite levels left in the meat after curing.

Research published in the Journal of Food Science (Tompkin et al., 1978) demonstrated that isoascorbate, ascorbate, and cysteine enhance the antibotulinal effect of nitrite in perishable canned cured meat.

With regard to regulatory use levels, according to USDA, 0.055% of either sodium ascorbate or sodium erythorbate is required to be added in pumped bacon.

Evidence strength: Mechanistically well-characterized; supported by controlled food science studies and regulatory standards. No clinical trials have specifically examined nitrosamine reduction in humans from dietary erythorbate intake.

5.3 Non-Heme Iron Absorption Enhancement

One of the most clinically relevant applications of isoascorbic acid is its capacity to enhance the bioavailability of dietary non-heme iron. A clinical study published in the American Journal of Clinical Nutrition (Fidler et al., 2004) specifically investigated this:

The addition of ascorbic acid at a molar ratio of 4:1 increased iron absorption 2.9-fold (11.7%; P = 0.0004). At a molar ratio of 4:1, erythorbic acid was 1.6-fold (P = 0.0002) as potent an enhancer of iron absorption as was ascorbic acid.

Because of its strong reducing properties, erythorbic acid has similar technological applications to ascorbic acid as a water-soluble antioxidant and is widely used as an additive in processed foods. However, the antiscorbutic activity of erythorbic acid is limited and has been reported to be only one-twentieth of that of ascorbic acid in guinea pigs. In humans, neither the antiscorbutic activity of erythorbic acid nor its physiologic activity as an antioxidant has been investigated in large-scale trials.

Erythorbic acid has shown promising results in reducing phototoxicity and increasing the absorption of nonheme iron, the latter providing a new modality of treatment for anemia.

Evidence strength: Human clinical trial evidence (Fidler et al., 2004, Am J Clin Nutr) supports the iron absorption-enhancing effect. The mechanism — reduction of ferric (Fe³⁺) to ferrous (Fe²⁺) iron in the gut — parallels that of L-ascorbic acid. Research in this area is limited to a small number of studies; further clinical investigation is warranted.

5.4 Antitumor Activity (Preclinical Evidence)

A study published in PMC (2017) examined the antitumor potential of high-dose intravenous erythorbic acid:

Intravenous (IV) infusion of high-dose ascorbic acid (AA) has been used as a treatment for cancer patients. The tumoricidal action of AA occurs due to its prooxidant effect. Erythorbic acid (EA), one of the AA epimers, has reduced vitamin C activity, while the antioxidant activity of EA is similar to that of AA.

The researchers examined the cytotoxicity of EA to murine colon carcinoma (colon-26) cells and the antitumor activity of EA in tumor-bearing mice. Cytotoxic activity of EA to colon-26 cells was evaluated by using the calcein-AM assay. EA showed the same cytotoxic activity to colon-26 cells as that of AA.

The cytotoxicity of EA was shown to be caused by oxidative stress. Colon-26 tumor-bearing mice were IV-administered EA and AA on alternate days for 4 times, and tumor growth rates were measured. High-dose erythorbic acid showed significant cytotoxicity to colon-26 cells. Tumor growth was inhibited by administration of high-dose erythorbic acid in vivo. High-dose IV erythorbic acid showed oxidative stress-mediated antitumor activity.

The antitumor activities of erythorbic acid were the same as those of ascorbic acid. Erythorbic acid may be used as an agent in infusion therapy for cancer.

Evidence strength: Preliminary animal and in vitro data only. No human clinical trials have investigated IV erythorbic acid in cancer patients. This area remains exploratory.

5.5 Collagen Synthesis

Isoascorbate has been studied in cell culture models for its ability to stimulate collagen synthesis, a biological property shared with, but weaker than, L-ascorbate. Research cited in the JECFA monograph (WHO Food Additives Series 28) reported:

Erythorbate also stimulated collagen synthesis but at considerably higher concentrations of 250–300 µM. The stimulation of collagen synthesis by ascorbate and erythorbate was accompanied by a decline in prolyl hydroxylase activity and a rise in lysyl hydroxylase activity; again ascorbate was the more effective.

In confluent human skin fibroblast cultures, D-ascorbate, D-isoascorbate, and L-dehydroascorbate also stimulated collagen synthesis but at considerably higher concentrations than L-ascorbate, which reached maximal effect at 30 µM.

Evidence strength: In vitro cell culture data only. No human clinical trials have examined topical or systemic isoascorbate for collagen synthesis or skin endpoints.

5.6 Phototoxicity Reduction

The therapeutic role of erythorbic acid is manifested by various in vitro as well as in vivo studies including antioxidant, antitumor, prevention of phototoxicity, stimulation of collagen synthesis, and ascorbic acid-protective activities. The phototoxicity-reduction evidence is referenced in several review documents but is based on preclinical (animal or in vitro) studies. Erythorbic acid has shown promising results in the treatment for different cancers as well as in reducing phototoxicity and increasing the absorption of nonheme iron.

Evidence strength: Preclinical only; human clinical evidence for phototoxicity reduction by isoascorbate as an isolated intervention is not currently available.

5.7 Antiscorbutic (Vitamin C) Activity

The antiscorbutic activity of erythorbic acid is limited and has been reported to be only one-twentieth of that of ascorbic acid in guinea pigs. Human metabolic studies confirm this sharp divergence. A study on the effects of erythorbic acid on vitamin C metabolism in young women (Sauberlich et al., referenced in AJCN) found that erythorbic acid and ascorbic acid were rapidly absorbed with little interaction, but erythorbic acid cleared from the body more rapidly than ascorbic acid.

In a controlled human depletion-repletion study reviewed in the JECFA monograph, after depletion of 24 days, subjects received increasing supplements of ascorbic acid (30 mg/d, 60 mg/d, and 90 mg/d for successive periods of 10 days) in the presence or absence of 600 mg/d of erythorbic acid. The depletion resulted in a marked decrease in ascorbic acid in all blood indices and during the study some subjects developed signs of scurvy. Erythorbic acid did not cause any adverse effects but rather had a small ascorbic acid-sparing effect.

D-isoascorbic acid has little or no vitamin C biological activity.

Evidence strength: Established by human clinical studies. Isoascorbate cannot substitute for vitamin C (L-ascorbic acid) in preventing or treating scurvy.

5.8 Interaction with Ascorbic Acid Metabolism

There has been regulatory and research interest in whether dietary isoascorbate — ingested through processed foods — might competitively interfere with vitamin C status. An NIH-funded investigation by Sauberlich specifically examined "whether isoascorbic acid is antagonistic to vitamin C in the human." Concern exists as to whether isoascorbic acid is antagonistic to vitamin C in the human; the overall goal of the proposed research was to determine whether the ingestion of isoascorbic acid in the diet has any beneficial or adverse effects on the human requirement for vitamin C.

The JECFA toxicological monograph review found that erythorbic acid did not act as an antagonist of vitamin C but rather demonstrated a mild sparing effect in depleted human subjects (Sauberlich et al., 1989). Furthermore, oxalate metabolism studies found that the urinary excretion of oxalate was examined in women receiving increasing increments of 30, 60, or 90 mg ascorbic acid per day for 10 days in the presence or absence of 600 mg/d of erythorbic acid. Increasing the ascorbic acid intake from 30 mg/d to 90 mg/d increased daily oxalate excretion by 67 µmol; but an intake of 600 mg/d of erythorbic acid increased daily oxalate excretion by 67–133 µmol — indicating that little if any of the erythorbic acid was metabolized to oxalate.

6. Body Systems and Health Areas

• Gastrointestinal / Nutritional: Enhancement of non-heme iron absorption (human clinical evidence); minimal antiscorbutic activity in humans; rapid renal clearance after absorption.
• Musculoskeletal / Connective Tissue: In vitro stimulation of collagen synthesis in human skin fibroblasts at higher concentrations than L-ascorbate; no human clinical evidence for this endpoint.
• Dermatological / Photoprotective: Preclinical evidence for reduction of phototoxic reactions; investigated in cosmetic patent literature as a component in formulations intended to promote elastin synthesis.
• Oncology (experimental): Preclinical (murine and in vitro) evidence for oxidative stress–mediated cytotoxicity toward colon carcinoma cells at high intravenous doses; no human trials.
• Cardiovascular / Food Safety: Reduction of N-nitrosamine formation in cured meat products, thereby reducing dietary exposure to known carcinogens; this is a food-processing rather than a clinical health endpoint.
• Immune / Antioxidant: Antioxidant activity in aqueous food matrices; no human clinical studies on immune system endpoints.

7. Regulatory Status and Dosage Forms

Regulatory Status

Safety when used as a food additive has been approved by the U.S. Food and Drug Administration (FDA), the European Food Safety Authority (EFSA), the Joint FAO/WHO Expert Committee on Food Additives (JECFA), as well as other authorities. It is generally recognized as safe (GRAS) when used in accordance with good manufacturing practices in food and feed.

It can be used as an antimicrobial agent, antioxidant, color or coloring adjunct, dough strengthener, flour treating agent, oxidizing or reducing agent, processing aid, and surface-finishing agent. Sodium erythorbate (E316) is listed in Commission Regulation (EU) No 231/2012 as an authorised food additive in the EU as "Additives other than colours and sweeteners."

Regulatory-Established Dosage Levels

• Used to control oxidative color and flavor deterioration in fruits at 150–200 ppm.
• Used in meat curing to speed and control the nitrite curing reaction and prolong the color of cured meat at levels of 0.05%.
• According to USDA, 0.055% of either sodium ascorbate or sodium erythorbate is required in pumped bacon.
• According to the European food safety assessment, erythorbic acid and sodium erythorbate in combination are authorized as food preservatives with highest permissible levels of 250–1500 mg/kg or mg/L in different food categories.

Dosages Reported in Scientific Studies

• Human depletion-repletion study (JECFA monograph, Sauberlich et al., 1989): Subjects received 600 mg/d of erythorbic acid alongside ascending doses of ascorbic acid (30, 60, and 90 mg/d for successive 10-day periods).
• Non-heme iron absorption study (Fidler et al., 2004, Am J Clin Nutr): Ascorbic acid at a molar ratio of 4:1 increased iron absorption 2.9-fold; erythorbic acid at a molar ratio of 4:1 was 1.6-fold as potent an enhancer of iron absorption as ascorbic acid.
• Collagen synthesis in cell culture (Murad et al., referenced in JECFA monograph): Erythorbate stimulated collagen synthesis at considerably higher concentrations of 250–300 µM.
• Antitumor study in mice (PMC, 2017): Colon-26 tumor-bearing mice were IV-administered EA and AA on alternate days for 4 times, and tumor growth rates were measured. No specific mg/kg dose was retrievable from the abstract data.
• In vivo lipid peroxidation study (guinea pigs): The protective effects of ascorbic and erythorbic acid against carbon tetrachloride-induced lipid peroxidation were investigated in guinea pigs; equal doses of 750 mg/kg b.w. (i.p.) of ascorbic acid or isoascorbic acid provided the same degree of protection for a period of at least 4 hours.

8. Safety Considerations and Interactions

Acceptable Daily Intake (ADI) and Overall Toxicological Profile

The EFSA Panel concluded that there is no reason to revise the current ADI of 6 mg/kg bw/day. An ADI 'not specified' was established at the 37th JECFA (1990), reflecting that at that time the Committee considered the toxicological data sufficient to conclude that the substance posed no appreciable risk at levels used in food. EFSA's subsequent re-evaluation, published in 2016, applied a more conservative ADI of 6 mg/kg bw/day based on updated review criteria.

According to available toxicological data, food additive E316 has low acute toxicity. Studies in laboratory animals have not revealed genotoxic or carcinogenic properties. No adverse effects on reproductive function or prenatal development have been reported.

No maternal and developmental effects were observed in a prenatal developmental toxicity study with sodium erythorbate. The Panel recognised the limitation of the overall toxicological database (no reproductive and chronic toxicity studies), but did not consider it necessary to increase the usual uncertainty factor of 100 in deriving an ADI.

Considering that the ADI is not exceeded by any population group, the Panel also concluded that the use of erythorbic acid (E 315) and sodium erythorbate (E 316) as food additives at the permitted or reported use and use levels would not be of safety concern.

Vitamin C Status: Lack of Antiscorbutic Activity

A documented and clinically significant safety concern is that isoascorbate cannot replace L-ascorbic acid as a source of vitamin C. In a human depletion study, the depletion resulted in a marked decrease in ascorbic acid in all blood indices and during the study some subjects developed signs of scurvy, despite erythorbic acid supplementation. Isoascorbate has only approximately 1/20th the antiscorbutic potency of L-ascorbic acid in guinea pig models. Any dietary context in which isoascorbate is consumed in substantial amounts but replaces L-ascorbate sources could theoretically compromise vitamin C status.

Interference with Plasma Vitamin C Assays

An important analytical safety consideration is that isoascorbic acid can interfere with plasma vitamin C measurements. A study published in PubMed (PMID 1962590) specifically examined the influence of dietary intakes of erythorbic acid on plasma vitamin C analyses, indicating that laboratories measuring vitamin C status in individuals who consume processed foods containing erythorbate must use assay methods capable of distinguishing between L-ascorbic acid and D-isoascorbic acid, as the two can co-elute in certain analytical systems.

Oxalate Excretion

There are indications that oxalate is a minor metabolite of ascorbic acid and high doses are associated with an increase in urinary oxalate. The urinary excretion of oxalate was examined in women receiving increasing increments of erythorbic acid alongside ascorbic acid; intake of 600 mg/d of erythorbic acid increased daily oxalate excretion by 67–133 µmol. This indicates that little if any of the erythorbic acid was metabolized to oxalate. This suggests that, unlike high-dose L-ascorbate supplementation, high dietary erythorbate is not associated with substantially elevated oxalate levels — though the dataset is limited.

Interaction with Benzoate-Containing Foods

There are concerns over benzoic acid forming benzene, a known carcinogen, in soft drinks containing vitamin C, as a result of reaction with ascorbic acid or erythorbic acid. This interaction is particularly relevant in acidic beverages where both benzoate preservatives and erythorbate (or ascorbate) are present, as trace metals such as iron and copper catalyze the benzene-forming reaction.

Population Considerations

In its scientific opinion on the re-evaluation of erythorbic acid and sodium erythorbate, EFSA concluded that the available evidence does not indicate health risks when the acceptable daily intake is respected. The EFSA Panel established an ADI of 6 mg/kg body weight. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the U.S. Food and Drug Administration (FDA) also do not classify additive E316 as hazardous when used in accordance with regulations. Potential risks may arise only in cases of systematic and significant exceedance of the ADI, which is considered unlikely under normal dietary conditions.

References

• WHO INCHEM: Erythorbic acid and its sodium salt — JECFA Monograph, WHO Food Additives Series 28 (JECFA 37th Meeting, 1990)
• WHO JECFA Database: Sodium erythorbate (INS 316)
• FAO: Erythorbic Acid — JECFA Specification Monograph 1 (2006)
• EFSA Journal (2016): Scientific Opinion on the re-evaluation of erythorbic acid (E 315) and sodium erythorbate (E 316) as food additives
• PMC: Oxidative stress-mediated antitumor activity of erythorbic acid in high doses (2017)
• American Journal of Clinical Nutrition: Erythorbic acid is a potent enhancer of nonheme-iron absorption — Fidler et al. (2004)
• PMC: Vitamin C — Sources, Physiological Role, Kinetics, Deficiency, Use, Toxicity, and Determination (2021)
• PubMed: Innovation in sodium erythorbate production: the use of membrane-reactors (2001)
• PubMed: Influence of dietary intakes of erythorbic acid on plasma vitamin C analyses
• American Journal of Clinical Nutrition: Effects of erythorbic acid on vitamin C metabolism in young women (Sauberlich et al., 1996)
• Journal of Food Science: Antibotulinal Role of Isoascorbate in Cured Meat — Tompkin et al. (1978)
• ScienceDirect Topics: Isoascorbic Acid — Overview
• ResearchGate: Erythorbic acid (D-ascorbic acid) — Chapter overview (2022)
• Center for Science in the Public Interest: Sodium erythorbate, erythorbic acid, sodium isoascorbate
• PubChem: Sodium Erythorbate (CID 23683938)
• FDA Substance Registration System: Sodium Erythorbate / Sodium Isoascorbate UNII
• NIH Grant: Effect of Isoascorbic Acid on Human Vitamin C Nutrition — Howerde Sauberlich
• International Journal of Toxicology / CIR: Final Report on the Safety Assessment of Erythorbic Acid and Sodium Erythorbate (1999)
• Earthworm Express: On the Mitigation of N-Nitrosamine Formation in Cured Meats: The Role of Ascorbate, Erythorbate, and Other Antioxidants